Current Research & Key Publications

Current Work:

Nanoparticles are the focus of scientific world in recent years due to their multiple applications for human welfare. Engineered nanoparticles are used in medical, pharmaceutical and therapeutic research, electronics, cosmetics, textiles, antimicrobial paints, ornaments, catalysis, battery and polymer industries, as semiconductors etc. Increasing demands, commercial production, application and usage of metal-based nanoparticles in various fields lead to their accumulation into the environment. Natural water, being the large environmental compartment, is likely to be the terminal repository of these nanoparticles which may pose risk to aquatic biota and associated ecosystem functions. Indeed, many studies with metal-based nanoparticles reported adverse biological effects. This in turn may pose risk to human via food chains / food webs. On the other hand some water soluble carbon-based non metallic nanoparticles have been revealed to have beneficial effects to living organisms. However, the knowledge on impacts to aquatic biota, cellular interactions, biochemical (enzymatic, genetic and proteomic) responses and mechanism of action of the nanoparticles is limited. Moreover, few controversial effects are also reported.

Investigating the physiological, cellular and biochemical responses to metallic nanoparticles (morphological alteration, biosorption and bioaccumulation of nano and/or ionic metals, intracellular reactive oxygen species (ROS) production, plasma membrane integrity, DNA strand breaks, extracellular Laccase production, antioxidant enzymatic activities, activities of neurotoxic biomarkers etc.) in the microbes (at different biological organizations: cellular, population and community levels) and invertebrates of freshwater detritus food web or those used as laboratory models and the underlying mechanisms / mode of action of nanometal-induced toxicity and role of bioavailable dissolved ionic metals released / leached from nanometals are the major concerns and interests of current research. We are studying the combined and individual biological (microbes and invertebrates) impacts of other emerging contaminants (e.g. pharmaceuticals, antibiotics, metals, other nanoparticles etc.) and environmental variance (warming, DOC, pH etc.) on the toxicity of metal nanoparticles, size dependent toxicity of metal nanoparticles and their interactions on aquatic microbes and invertebrates with mechanistic explanations in lentic and lotic systems. Additionally, developments in the approach of molecular proteomics, transcriptomics and genomics are ongoing to understand the stress responses of aquatic microbes to nanoparticles.

In contrary, our recent study revealed growth stimulatory and antioxidant impacts of non-metallic carbon-based nanoparticles in yeast with mitigation of ionic metal-induced oxidative stress monitoring the intra- and extracellular interactions (including ligand-binding properties) between nanoparticles and ionic metals which could be potentially implicated in toxicant remediation processes and nanomedicinal and nanotherapeutic fields. We are also investigating the impacts and mode of action of carbon-based nanoparticles as an antioxidant against the nanometal-induced oxidative stress in yeast considering the interactions with macromolecules of media as an approach for the environmental friendly cleaner and biocompatible nanotechnology.

2. AGRHYDROM - A timely look at effects of agriculture on fluvial dissolved organic matter: the role of hydrology, project J-AIL 2016-2018, a collaborative project from Youth Iberian Association of Limnology (Youth-AIL or Jóvenes-AIL) – As participant.

3. PestiSense - Novel tools and data for the detection and assessment of ecological risks of pesticides, 2017-2018, a collaborative project among the post-doctoral researchers from three different research groups of CBMA – As participant (also spokeperson).

2. NANOECOTOX-Impacts of metal nanoparticles to aquatic ecosystems: from community responses to cellular targets, PTDC/AAC-AMB/121650/2010, 2012–2015 (Budget € 184296) at CBMA, Department of Biology, University of Minho, Braga, Portugal – As team member (75%) during March 2012–April 2013 and as Research Grantee (100%) during May 2013–September 2015.

3. (Micro)analysis of nanoparticles on aquatic fungi, FCT-DAAD-2010-2011, Transnational Cooperation – as team member at CBMA, Department of Biology, University of Minho, Braga, Portugal, Martin Luther University, Halle, Germany and Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany – As team member.

2. Pradhan A. 2014. “Impacts of nanoparticles to microbes and invertebrates: from community responses to cellular targets”. Biotechnology Alumni Seminar Series, 2014, October 27, West Bengal University of Technology, Kolkata, India.

8. Pradhan A. 2015. “Impacts of nanoparticles to microbes and invertebrates: from community responses to cellular targets”. 9th Symposium for European Freshwater Sciences (SEFS9), July 5-10, Geneva, Switzerland. Invited for poster presentation on PhD research by association of European Fresh and Young Researchers (EFYR) as winner of EFFS (European Federation for Freshwater Sciences) subsidiary Award 2015 for Best PhD Dissertation (2013-2014) in Freshwater Sciences.